Artificial boards and shapes

ABSTRACT

A method and apparatus for producing elongated boards of artificial lumber reinforced with elongated reinforcing members providing strength thereto. The boards are constructed of any suitable filler material such as ligneous fibers mixed with thermosetting resin. The mixture of fibers and resin are pulled into a compression chamber by a plurality of elongated belts while the reinforcing strands are fed thereto. The belts are rotated to compress the mixture about the strands while the strands are under tension or undulated. Then the mixture is fed through a curing chamber for curing.

This is a division of application Ser. No. 321,153, filed Jan. 5, 1973,now U.S. Pat. No. 3,890,077.

This invention relates to a method and apparatus for producing elongatedboards of artificial lumber and more particularly to a method andapparatus for pulling a mixture, which is compressed about elongatedreinforcing strands, through a curing chamber.

Heretofore many attempts have been made to produce compressed boardsfrom various materials such as ligneous fibers mixed with a bondingagent, however, it has been difficult to obtain a breaking strengthsimilar to that of high grade lumber. An attempt to reinforce theartificial lumber with reinforcing members is disclosed in U.S. Pat.Nos. 2,717,420 and 2,847,733. As a result of the mixture being ramextruded, segmented, compressed portions are produced with the strengthof the material at the gaps between the segmented compressed sectionsbeing less than the strength at other points on the surface of thematerial that is compressed.

Another method of manufacturing fibrous extrusions is illustrated inU.S. Pat. No. 2,648,262 which discloses an apparatus for the manufactureof fibre board by use of a reciprocating ram. As can be seen theseboards are not reinforced and therefore do not possess the strength of aboard constructed of similar material reinforced with elongatedreinforcement strands.

Accordingly, it is an important object of the present invention toprovide an apparatus for constructing elongated boards of artificiallumber which are reinforced with elongated strands extending the lengthof the lumber.

Another important object of the present invention is to provide anapparatus for drawing and compressing fibrous material into desiredshapes while reinforcing the shape with elongated strands of fibrousmaterial.

Still another important object of the present invention is to provide anelongated board constructed in accordance with the present inventionwith reinforcing strands which are oriented in predetermined patterns toadd strength thereto.

Still another important object of the present invention is to provide anapparatus for producing elongated artificial boards which have strandsextending therethrough that were texturized prior to forming the boardswith such therein.

Still another important object of the present invention is to provide amethod of constructing an artificial board of any desired length whichis reinforced with reinforcing strands and has a substantially uniformdensity about its length.

Still another important object of the present invention is to provide amethod of reinforcing elongated artificial boards with reinforcingmembers which are under tension.

Still another important object of the present invention is to provide amethod of compressing material by use of elongated belts into a desiredlength while reinforcing strands are fed thereto.

Still another important object of the present invention is to provide asimple and economical method and apparatus for constructing artificialboards having a cost comparable with natural lumber.

The construction designed to carry out the invention will be hereinafterdescribed, together with other features thereof.

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawingsforming a part thereof, wherein an example of the invention is shown andwherein:

FIGS. 1 and 2 is a side elevational view illustrating an apparatus formanufacturing artificial lumber,

FIG. 3 is an enlarged plan view taken along lines 3--3 of FIG. 2,

FIG. 4 is a sectional view taken along line 4--4 of FIG. 3 illustratinga mixture being compressed into artificial lumber,

FIG. 5 is a large perspective view with parts broken away illustrating amodified form of a board constructed in accordance with the presentinvention,

FIG. 6 is a perspective view with parts broken away illustrating aportion of the artificial lumber manufactured in accordance with thepresent invention,

FIG. 7 is a partially diagrammatic perspective view illustrating thearrangements of the belts utilized for compressing and pulling theartificial lumber through a compression member and curing chamber,

FIG. 8 is a fragmentary perspective view illustrating a modified form ofthe invention wherein reinforcing fibers are reciprocally shiftedlaterally prior to compressing with the mixture to form the artificialboard,

FIG. 9 is a perspective view illustrating another modified form of theinvention wherein the board is reinforced with undulated elongatedstrands, and

FIG. 10 is a modified form of the invention wherein elongated strandsare texturized prior to being fed into the compressing and curingmembers.

Referring in more detail to the drawings there is illustrated anapparatus for producing elongated boards of artificial lumber and shapesfrom a mixture of fibers and a heat activated binder reinforced withelongated reinforcing members. A plurality of endless belts are radiallyspaced about a longitudinal axis. Rotatable members support each of thebelts in an extended loop with the belts being positioned about thelongitudinal axis so that an inner surface of each of the beltscooperate to define an elongated forming die A with an entrance openingat one end and an exit opening at the other end. A hopper means B isprovided for supplying the mixture of ligneous fibers and resin to theentrance of the elongated forming die A. Means C is provided for feedingelongated reinforcing members to the elongated forming die A. Heatersare carried closely adjacent an inner surface of the belts for curingthe mixture as such passes through an elongated curing chamber D. Meansis provided for rotating the belts defining the forming and curing diesA and D for pulling the mixture and the elongated reinforcing membersthrough the elongated dies forming an elongated reinforced curedartificial board. Means is also provided for placing said elongatedreinforcing members under tension as said mixture and reinforcingmembers are pulled through said forming die A.

Referring in more detail to FIGS. 1, 2 and 3 of the drawings there isillustrated an apparatus for producing elongated boards of artificiallumber. The apparatus is supported on a bed 10 of an elongated metaltable. The bed 10 of the table is supported on vertical posts 12 spacedlongitudinally thereunder. Suitable elongated bracing such as horizontalangle irons are provided for adding rigidity to the table.

The mixture which is used to form the elongated board is fed into ahopper means B and deposited on an elongated bottom belt 16. This bottombelt 16 is constructed of steel and extends substantially the fulllength of the table 10 and passes under the hopper B for receiving themixture therefrom. The belt 16 is provided for rotating on the rollers18, 19, 20, 21 and 22 as illustrated in FIG. 6 of the drawings. Theportion of the belt between roller 22 and roller 18 is carried above thebed of the table and in some particular embodiments a bearing means isprovided between the belt and the surface of the table. These bearingmeans may include roller bearings or in some particular instances a lowfriction plastic material such as nylon strips. Such are not illustratedfor purposes of clarity. Positioned closely adjacent the bottom belt 16are a pair of spaced side belts 22 and 24 respectively. The side belts22 extends around rollers 26 and 28 carried adjacent opposite ends ofthe elongated table and on one side of the hopper B. The elongated belt24 is carried on the opposite side of hopper B closely adjacent thebottom belt 16 and extends around rollers 30 and 32. It is noted thatthe forward end portions of the belts 22 and 24 converge inwardlytowards a longitudinal axis 34 extending through the curing die A. Angleiron members are provided for guiding the belt in the converging manner.After the belts converge so that the distance between the inner surfacesof belts 22 and 24 reaches a predetermined distance then the beltsextend rearwardly parallel to the longitudinal axis 34 until they reachthe rear rollers 28 and 32. As shown in FIG. 4 angle irons such as shownat 36 and 38 are bolted to the table 10 with bolts 40 for guiding thedirection of the side belts 22 and 24.

In order to compress the material being fed from the hopper B in theforming die an upper belt 42 is carried directly above the side belts 22and 24 and the bottom belt 16. The forward end of the upper belt iscarried on a roller 44 with the rear end extending around a roller 46.Roller 44 is positioned slightly higher than roll 46 so that the belt 42extends downwardly towards the longitudinal axis of the forming die.

The forming die A is defined by the inner surfaces of the upper belt 42,side belts 22 and 24 and bottom belt 16. As the material is being fedthrough the hopper B onto the bottom belt 16 it is pulled through theforming die A by the rotation of the belts 16, 22, 24 and 42 so as to becompressed to a predetermined height and width such as illustrated inFIGS. 3 and 4.

Positioned directly ahead of the top belt 42 is a speed roll 48 which isrotated at a much higher speed than the belts being used to compress thematerial so as to place a polished, finished surface on the compressedmember. In some instances the speed roll 48 is used to further compressthe mixture for placing a desired configuration on the surface that itis engaging. The compressed board 49 is then pulled through a curingchamber D which is defined by an elongated upper belt 50, the bottombelt 16 and the two side belts 22 and 24 respectively. Heaters 49a arecarried adjacent the inner surface of each of the belts 22, 24, 16 and50 for applying heat to the compressed mixture being pulled therethroughfor curing the thermosetting resin to solidify the board. The curingchamber D may be of any desired length depending on the speed that theapparatus is being operated. Of course if it is desired to operate theapparatus at a higher rate of speed then it would be necessary to makethe curing chamber D much longer so that the resinous material will bein contact with heat for the desired length of time. Suitable controls52 are provided for controlling the heat of the heating elements carriedunder the insulated cover 54 shown in FIG. 1.

All of the elongated steel belts are driven from a single drive motor 56(FIG. 1). The drive motor 56 is coupled to a vertical shaft 58 by meansof a chain extending around pulley 60. Two small output pulleys 62 and64 are carried on the shaft 58. Extending around the pulleys 62 and 64are elongated chains which also extend around the pulleys of a gearbox64a. The chain 62a is coupled to an input pulley 62b which drives avertical output shaft 62c of the gearbox 64. The vertical output shaft62c in turn has wrapped therearound a chain 62d which is coupled to theshafts 62e and 62f upon which the rollers 28 and 32 are carried. All ofthe pulleys are not illustrated for purposes of clarity. It is to beunderstood of course, that the rollers 28 and 32 are driven from thegearbox 64 at the same rate of speed as the other chains used on theapparatus. Chain 65a which is coupled to pulley 64 is used to drive theinput shaft of the gearbox which in turn rotates the horizontal outputshaft 65b. The horizontal output shaft 65b in turn is coupled to a chain65c which extends around pulleys 65d and 65e. Pulley 65d is carried onthe end of the same shaft that drum 50b is carried for driving the belt50. The sprocket 65e is carried on a shaft which in turn has a geararrangement (not shown) provided thereon for driving a sprocket 65f.Extending around sprocket 65f is a chain 66 that is used for driving thepulley 67 carried on the same shaft upon which roller 18 is provided.This in turn drives the elongated belt 16.

The power for driving the top belt 42 is derived from the vertical shaft68 upon which the roll 32 is carried. The roller 32 is rotated when theside belt 22 is driven in turn causing a gearbelt 70 which is carried onthe same shaft 68 to be driven. The other end of the gearbelt 70 iscarried on a pulley 72. The pulley 72 is carried on shaft 74 upon whichroller 44 is carried for rotating the roller 44 and in turn the top belt42. Keyed to the other end of the shaft 74 is a sprocket 76 upon which achain 78 extends to drive roller 46 through a sprocket 80 carried on theend of shaft 82. The shafts 82 and 74 are suitably journalled in bearingblocks 86. All of the shafts upon which the belts 22, 24, 16, 50 and 42extend around are journalled in similar bearing blocks and such are notdisclosed and described for purposes of clarity.

Forming die A includes side belts 22, 24, a bottom belt 16 and top belt42. From viewing FIGS. 3 and 6 it can be seen that the side beltsconverge inwardly towards a longitudinal axis 34. The top belt 42 alsoconverges rearwardly towards the longitudinal axis 34. As the material,which is generally a filler material, and a binder is dispensed from thehopper B onto the bottom belt 16 it is fed through forming die A to becompressed by the belts 42, 22, 24 and 16 to the desired cross-section.When the compressed board leaves the trailing roller 46 around which thebelt 42 is carried it then passes under a speed roller 48 which isdriven by electric motor 90. An output shaft of electric motor 90 iscoupled through belts 92 and 94 to a pulley 96 carried on the shaft 98upon which the speed roll 48 rides. The shaft 98 is suitably journalledin bearing blocks 100. The speed roll 48 which operates at a much higherspeed than the speed that the belts pulling material through the formingdie A and curing chamber D operate places a final shaped polishedsurface on the artificial lumber being formed.

Elongated reinforcing fiberglass strands 102 are carried on a creel 103having a plurality of packages 104 rotatably carried on horizontal framemembers 106. The strands are fed off the individual packages 104 throughguides 106 around a pair of spaced rods 108 and 110. The purpose of thespace rods is to impart tension on the strands as they are pulledthrough the forming die A and curing chamber D during the manufacture ofthe artificial lumber. The strands 102 as illustrated in FIG. 2 are fedunder rod 108, over rod 110 around rod 112 and back under rod 114. Therods 108, 110, 112 and 114 are carried between spaced brackets 115 and116 respectively. By rotating these brackets the frictional contactcaused by the strands 102 passing around the rods can be varied. Thebracket 115 is allowed to rotate about pin 117 which is suitablysupported on spaced upper angle iron members 118. The fiberglass strands102 then pass under another guide member 120 which has a transverse rod121 carried between the space members 122. The strands 102 then passthrough a die 123 which has holes extending therethrough for maintainingthe strands separated according to a predetermined pattern as thereinforcing strands 102 pass beneath the hopper B. In order to form thepattern shown in FIG. 4 of the drawing which simulates woodgrain the die123 positioned in front of the hopper has a plurality of alignedhorizontal and vertical holes extending therethrough through which thestrands 102 extend. The arcuate shape of the pattern of each column ofstrands 102 shown in FIG. 4 is produced when the mixture is compressedin the compression member A.

It is noted that the restraining members 116 and 120 are carried withinan elongated receptacle 125a defined by converging side walls 125 and126 which are connected by a bottom 127. Resin is carried within thisreceptacle 125c for coating the fiberglass strands 102 as they passtherethrough for enhancing the bonding between the fiberglass strandsand the mixture being fed through the hopper B.

The hopper B is rectangular shaped and includes vertical side walls 128and 129 which are joined by end walls 130 and 131. A trough 132 (notshown is FIG. 3 for purpose of clarity) is carried adjacent the top ofthe hopper for feeding a mixture into the hopper. The upper end of thetrough is supported by vertical angle irons 133. Rollers 134, 135 and136 are carried between the side walls 128 and 129 of the hopper forbeing rotated to throw the mixture between the spaced strands 102 offiberglass. The upper roller 134 is rotated to feed the mixture from thetrough 132 downwardly towards the two lower rollers 135 and 136. Therollers 135 and 136 are rotated in opposite directions to engage themixture and throw such between the fiberglass strands. Positioned on therollers 134, 135 and 136 are outwardly extending pins which engage themixture to move such through the hopper. The pins on the lower rollers135 and 136 are aligned in a predetermined pattern so that they arecircumferentially spaced around the rollers 135 and 136 in rows thatintersect between the strands extending through the die 123 below thehopper B so as to pack the mixture between the fiberglass strands 102.

An electric motor 138 is provided for driving the three rollers 134, 135and 136 by means of a belt 139 extending around pulleys carried on theends of the shafts which support the rollers 134, 135 and 136.

One suitable mixture that can be placed in the hopper for beingcompressed around the elongated fibers 102 consists of the followingformulation by weight.

    ______________________________________                                        Pine or Oak wood fibers - medium fine -                                        1/16 to 5/8" long                                                             18 to 20 hundredth of an inch thick                                                                    32.5%                                               Pine or Oak wood fiber - fiberized -                                           .15 to 3/4" long         3.25%                                               Pine or Oak wood flour - 95% passes through                                                             7.4%                                                a 60 mesh screen                                                              Bonding resin - thermosetting polyester                                                                 6.4%                                                Fire retardant powder - aluminum hydrate                                                                3.25%                                               Urea resin - 60% solids   44.0%                                               Wax - Microcrystalin paraffin emulsion                                                                  3.2%                                                60% solids                                                                    (aids in making board water resistant)                                        Reinforcing members - fiberglass strands                                                                .12 lbs./ft.                                        Bonding resin for coating reinforcing members                                  Orthophthalic polyester resin - 50% base alkyd                                                         .24 lbs./ft.                                        ______________________________________                                    

It is to be understood that many variations of the above formulation maybe utilized and it is contemplated that waste materials such as sawdust,wood fibers, processed garbage, trash and many other items which can bebonded under heat and pressure with a thermosetting resin may beutilized. Also many suitable additives may be included in the mixturefor repelling termites, making the board fire-resistant, waterresistant, and conditioned against other environmental conditions.

In summarizing the method and apparatus for producing artificial lumberutilizing the apparatus as disclosed in FIGS. 1, 2, 3, 4 and 7 first theelongated fiberglass strands 102 are threaded from the creel 103 aroundthe restraining members 115 and 116 through a resinous material carriedin the receptable 125a that in one particular embodiment is anorthophthalic polyester resin having a 50% base of alkyd. As theelongated strands are fed through the receptacle 125a the resinousmaterial is coated on the strands 102. The strands 102 then pass througha die 123 to be oriented in horizontal rows and vertical columns. As theelongated strands pass under the hopper B the mixture of ligneousmaterial is thrown between these strands onto the bottom belt 16. Ofcourse at this time all of the belts forming part of the apparatus arerotating at the same rate of speed since they are all driven from thedrive motor 56. As the mixture is placed on the bottom belt 16 theconverging side belts 22 and 24 begin compressing the mixture. Themixture then passes under the top belt 42 which is rotating in the samedirection as the two side belts 22 and 24 and the bottom belt 16. Theinner surface of the top belt 42 as well as the inner surface of theside belts 22 and 24 all converge towards the longitudinal axisextending through the forming die A defined by the belts. As the mixtureis pulled through the compression chamber A by the belts 16, 22, 24, and42 such is compressed. Due to the action of the side belts 22 and 24compressing the mixture from the sides the fiberglass strands whichoriginally started out in columns are compressed into arcuate columnssimilar to the grain of wood such as illustrated in FIG. 4. These curvedoriented columns of fiberglass strands 102 increase the strength of thewood product.

As the compressed mixture passes under roll 46 it has completed thecompression and the speed roll 48 which is rotating at a much higherrate of speed polishes the upper surface of the material. The materialis then fed under the curing chamber D by the side belts 22 and 24,bottom belt 16 and a top belt 50. As previously mentioned, elongatedheating elements are carried closely adjacent the inner surfaces of theelongated belts for curing the compressed board as it passes through thecuring chamber D. Since the mixture is being pulled or drawn by thebelts 22, 24, 16, 42 and 50 and the restraining members 116 and 115frictionally engage the strands 102 passing therearound the elongatedstrands 102 are placed in tension. In one particular embodiment twohundred pounds of tension is applied to the strands being fed into themixture. By placing the strands under tension the strength of the woodis substantially increased.

FIG. 8 illustrates a modified form of the invention when instead ofaligning the elongated strands 102 by means of a die having alignedvertical and horizontal holes extending therethrough for separating thestrands the die is constructed of three pieces. The upper and lowermembers 141 and 142 respectively are rectangular in shape and have rowsof aligned holes provided therein through which the elongated strandsextend. These members 141 and 142 are fixed closely adjacent theentrance of the hopper B by means not shown for purposes of clarity.Sandwiched between the two members 141 and 142 is a central member 143that has spaced holes 144 extending therethrough. By reciprocally movingthe central member 143 back and forth as the fibers are being drawnunder the hopper D a sinusoidal pattern is applied to the centralstrands 102 compressed in the board. This adds considerable strength tothe board. The fibers that pass through the upper and lower members 141and 142 would be oriented in the same way as the upper and lower fibersillustrated in FIGS. 4 and 6. The mechanism for reciprocating thecentral member 143 back and forth includes a linkage of 145 which hasone end pivotally attached to the central member 143 and the other endattached by a pin 146 to a disk shaped member 147. This pin 146 isspaced radially from the axis upon which the disk shaped member 147 isrotated. An electric motor 148 is provided for rotating the shaft 149upon which the disk shaped member 147 is carried.

FIG. 10 is a schematic illustration of a modified form of the inventionwherein the elongated fibers 102 are fed through a bath 150 including amixture of resin and filler material such as ground up corn cobs. In oneparticular embodiment the resin material used for coating the elongatedstrands 102 is orthophthalic polyester resin mixed with ground up corncobs which is capable of being retained on a 40 mesh screen and isallowed to pass through a 20 mesh screen. As the resinous material andcorn cobs are adhered to the fiberglass strands 102 they are passedthrough a die 151 having holes therein for removing the excess resinousmaterial therefrom. The coated strands are then passed under heatinglamps 153 for producing a stage B (partial curing) of the resinousmaterial. The partially cured resinous material and corn cobs adhere tothe elongated strands and produce a rough and uneven surface on thestrands which enhances the bonding of the mixture being fed by hopper Bto the elongated strands. The elongated strands then pass through a die152 to be oriented similar to the die 131 as shown in FIG. 3.

FIG. 8 shows diagramatically the elongated strands 102 provided in anartificial board 49 having the uneven or texturized surface produced bythe corn cobs mixed with resinous material.

FIG. 9 illustrates still another modified form of the invention whereinthe fiberglass strands 102a are crimped by any suitable means such asheated crimping rolls to produce an undulated wave form therein. Thesefiberglass strands are then fed into the apparatus shown in FIGS. 1through 4 to be mixed with the mixture. Of course the tension must bereduced when utilizing undulated fiberglass strands so that theundulations will remain therein as the compressing operation takesplace.

The elongated board produced by the method and apparatus described abovehave a substantially uniform density about its length produced bycompressing the mixture with elongated rotating belts. The core of theelongated board has a density less than the density of the outer layers.As a result of producing the board with its outer layers having auniform density about its length, the overall strength of the board hasa higher strength rating than if it were produced by joining compressedsegments such as the case inherent in ram extrusion.

While a preferred embodiment of the invention has been disclosed it isto be understood that the apparatus may be used for compressing anysuitable mixture of materials that is capable of being bonded withresinous materials and cured.

What is claimed is:
 1. An elongated board of artificial lumber having alength much greater than the width and thickness and being of apredetermined thickness comprising: a homogeneous mixture of ligneouswood fibers and a cured thermosetting resin, a plurality of spacedelongated reinforcing strands extending the length of said board, saidfibers and said resin on opposite sides of said board being compressedto said predetermined thickness and densified by having been heated andcompressed under pressure while being held at said predeterminedthickness defining smooth continuous outer layers having a substantiallyuniform density about the length of said board, a continuous coreextending the length of said board having a density less than said outerlayers, and said homogeneous mixture of fibers and resin forming a bondaround said elongated reinforcing strand affording longitudinal andtransverse strength to said board.
 2. The elongated board of artificiallumber as set forth in claim 1 wherein said elongated reinforcingmembers extending through said elongated board have an undulatedconfiguration.
 3. The elongated board of artificial lumber as set forthin claim 1, wherein said elongated reinforcing strands are fiberglassstrands.
 4. The elongated board of artificial lumber as set forth inclaim 1, wherein said elongated reinforcing strands are under tension.5. The elongated board of artificial lumber as set forth in claim 1further comprising: a textured coating carried on said elongatedreinforcing members producing an uneven surface for enhancing bonding ofsaid fibers and resin to said elongated reinforcing strands.
 6. Anelongated board of artificial lumber having a length much greater thanthe width and thickness comprising: a homogeneous mixture of ligneouswood fibers and a cured thermosetting resin, a plurality of spacedelongated reinforcing strands extending the length of said board, saidfibers and said resin on all sides of said board being compressed anddensified by having been compressed under pressure defining smoothcontinuous outer layers on all sides having a substantially uniformdensity about the length of said board, a continuous core extending thelength of said board having a density less than said outer layers, andsaid homogeneous mixture of fibers and resin forming a bond around saidelogated reinforcing strands affording longitudinal and transversestrength to said board.